KTD-N0886-E
Page 31
Internal Connectors
KTQM87/mITX Users Guide
Fan Connectors (J28 and J29)
7.2
The FAN1SYS (J28) can be used to power, control and monitor a fan for chassis ventilation etc.
The FANCPU (J29) is used for the connection of the FAN for the CPU.
The 4pin header is recommended to be used for driving 4-wire type Fan in order to implement FAN speed
control. 3-wire Fan support is also possible, but no fan speed control is integrated.
4-pin Mode:
3-pin Mode:
Signal
Description
PWM
PWM output signal for FAN speed control.
TACHO
Tacho input signal from the fan, for rotation speed supervision RPM (Rotation Per Minute). The
signal shall be generated by an open collector transistor or similar. Onboard is a pull-up
resistor 4K7 to +12V. The signal has to be pulsed and onboard circuit is prepared for two pulses
per rotation.
12V
+12V supply for fan. A maximum of 2000mA can be supplied from this pin.
GND
Power Supply GND signal
Header
Pin
Signal
Description
Type
1
PWM
PWM output
O-3.3
2
TACHO
Tacho signal
I
3
12V
Power +12V
PWR
4
GND
Ground
PWR
Header
Pin
Signal
Description
Type
1
Not used
2
TACHO
Tacho signal
I
3
12V
Power +12V
PWR
4
GND
Ground
PWR
